Fig. 1

2D NMR acquisition with pulse sequences of (a) saturation recovery and (b) inversion recovery

Fig. 2

Echoes acquired by 2D NMR with (a) saturation recovery and (b) inversion recovery sequences during laboratory core measurement

Table 1

Parameter settings for different acquisition sequences shown in Fig. 2

Fig. 3

T2-T1 2D NMR spectra of shale oil core sample obtained from (a) saturation recovery and (b) inversion recovery acquisition sequences

Fig. 4

T2-T1 spectra of shale oil core sample with oil-saturation obtained with different echo interval (TE) values using inversion recovery acquisition sequences on a 21 MHz instrument. (a) TE=0.1 ms; (b) TE=0.2 ms; (c) TE=0.4 ms; (d) TE=0.6 ms

Table 2

Comparison of the signal intensity of T2-T1 spectra acquired at different echo intervals shown in Fig. 4

Fig. 5

T2-T1 spectra of shale oil core samples obtained from saturation recovery acquisition sequence with 14 sets of echo at 0.08 ms echo interval and different magnetic field strengths. (a) Resonance frequency of 2 MHz；(b) Resonance frequency of 21 MHz

Fig. 6

T2-T1 spectra of shale oil core sample with oil-saturation obtained using 0.08 ms echo interval and inversion recovery acquisition sequence with different waiting time echo groups on 21 MHz instrument. (a) 15 groups; (b) 9 groups; (c) 5 groups; (d) 3 groups

Fig. 7

T2-T1 spectra obtained using different echo interval (TE) values for full diameter cores. (a) TE=0.4 ms；(b) TE=0.8 ms

Fig. 8

T2-T1 spectra at an echo interval of 0.4 ms using different minimum waiting times (Tw) values for full diameter cores. (a) Minimum Tw = 1 ms; (b) Minimum Tw = 2 ms; (c) Minimum Tw = 5 ms; (d) Minimum Tw = 10 ms

Fig. 9

Shale oil NMR logging results

Fig. 10

T2-T1 2D NMR spectra obtained from NMR logging data with a smoothing factor of 1.0 and using different deployment ranges. (a) 0.1~10 000 ms symmetrical placement; (b) 0.5/1.0 ~3 000 ms asymmetric placement

Fig. 11

T2-T1 spectra of NMR logging data with smoothing factors of (a) 0.5, (b) 1.0, (c) 5.0, and (d) 10.0

Fig. 12

T2-T1 spectra of reservoir data with different signal-to-noise ratios